The present invention relates to a dot-matrix printer with a font cartridge unit which reads out, e.g., high-density character pattern data stored in the font cartridge unit in advance and performs dot printing in accordance with the readout data.
Some dot-matrix printers can perform high-density dot printing corresponding to the printing quality of a fully formed character obtained by a fully formed character printer. Such a dot-matrix printer comprises a read-only memory (ROM) storing high-density character pattern data in addition to character pattern data corresponding to standard characters. The dot-matrix printer reads out desired character pattern data from this ROM, and performs high-density dot printing corresponding to the readout data.
Printing characters usually have different patterns varying, e.g., with countries. For this reason, if the dot-matrix printer comprises a ROM storing character pattern data for respective countries, a ROM requiring large capacity is needed, resulting in high total cost of the printer. In order to overcome such a drawback, ROMs respectively storing character pattern data corresponding to the respective countries are prepared in advance, and the corresponding ROM is selected as needed and is mounted on the dot-matrix printer. However, in this case, a storage capacity of the ROM mounted on the printer is fixed, and the number of types of fonts of characters to be printed is limited.